Why is there a button at all? Record everything all the time. Sort it out later. The vast majority of it will be useless footage, but so what? If I was a cop I

Why is there a button at all? Record everything all the time. Sort it out later. The vast majority of it will be useless footage, but so what? If I was a cop I would certainly want every donut I eat to be recorded if it also means there is no change I get falsely accused of improper interaction with the public. 99.9% of the time no one will look at my donut footage.